Viscometry is a widely used measurement method to help determine the physical properties of particles and molecules in solution. Generally used in conjunction with size exclusion chromatography (SEC), also known as high performance liquid chromatography (HPLC), these instruments measure the differential viscosity between a sample bearing solution and a reference liquid, and are hence referred to as differential viscometers. The specific viscosity of the sample may then be determined, and from this value, and knowledge of the sample concentration, the intrinsic viscosity of the sample may be derived. When viscometric and concentration measurements are further coupled with multi-angle light scattering measurements, further information regarding molecular conformation and molecular interactions may be determined.
A critical, and expensive, component of differential viscometers is the pressure transducer. As sample fluids flow through the transducer, its wetted surfaces are prone to corrosion due to exposure to the sample solvent. It is an objective of the present invention to provide a transducer with sensor bodies which are highly corrosion resistant. Another wetted element of viscometer is the sensing membrane which is generally sandwiched between two pressure transducer halves. This element is also susceptible to corrosion. It is a further objective of this invention to improve the lifetime of the sensing membrane.